Screening apparatus



June 5, 1923. A v1,457,810 A P.. J. ALWART SCREENING APPARATUS Filed Feb. 18. 1921 Patented June 5, 1923.

PAUL' J. ALWARRT; or cHIcAeo, rLrfrrmrsQV SCREENING yArinerinrlrs.V

v'Application filed February 18', '1921. Serial No. 445,980.

T0 all whom it may camera: l .f

Be kit known that 1,; PAUL'J. ALwAn'r, a citizen ofthe UnitedStates, and a resident of Chicago, CookCounty, a-nd State of-Illinois, have invented certain new and useful Improvements in Screening' Apparatus,gof

which the following is declared to be a full,-

ciear.- and exact description. l

This inventiony relateshto screening apparatus and it has reference moreparticularly to4 cushioningmea-ns, whereby the' con.- stant jars and shocks, which are due to the vibratory or shaking movement imparted to' the screen by the agitating means, may ,be taken up, whereby ,the wear and tear'on the various parts is reducedv to a minimum. This invention pertainsto coalscreens or other screens for screening heavy, coarse material, such as. gravel,v and l so forth. j The wear andV tear on suchscreens i's'considerable and one ofthe objects o 'f the present, invention is to lessen the jar and shock, andl thereby prevent 4the-usual rapidbreaking down of the structure.t -Anotherobject is to provide simple and eflicient means in an'inclined screeningiapparatusnfor holding the screen againstl lengthwise-fior endwise movement. The'invention consists in the several novel features hereinafter fully set forth and claimed. i D

The invention is clearly illustrated in the accompanying drawings, in 'whichzr 1g. l is a Avertical longitudinal section of a screening apparatus embodying a simple form of the-present invention.; Fig. 2 is a cross section taken on the line of Fig.

l; Fig-3 is an end view loo-king in the di-v rection of the` arrow 3 invlFig. l; Fig. 4 is a detail, vertical, longitudinal section taken ori-line 11i-4i of Fig; 3, and Fig. 5 Ais adetail section taken on line 5-5 Of Fig. 3. K

Referring to said drawings which `illustrate a simple embodiment of the invention, the y*reference cl'iaracterI 1-1 designates the main frame or structure and 12 an inc-lined chute or hopper` bottom ofi ahopper orr containery forfthe material to be screened.H The screen 21-is preferably rectangular *informA and-incli'nes downwardly from-the lower end of said hopper bottom l2`r and comprises lengthwise screen frame members 27 and end` [screen framefinenrbers 27a which are securely fastened together to make up a strong and substantial screen frame. A wire mesh or perforated plate screen 30 is secured to the screen frame. The screen 21 stationary frame members,l 26,' `whichgrun parallel Awith the screen and. are ysupported at .one endv `by the main structure and i at. the otherend legs l,or braces ,25.y End'l frame" members 26a connect the' inclined frame members 264 A,Hinged material retarding gates 31- are rhingedly supported by fthe: stationary frame members 26 'and` extend therebetween with their lower'edges vresting on the screen. y

`Cams 23, located near each Y' end; of Athe screen, arefemployed for ,vibratingor.;agitat-r ing the screen, said cams being .mountedjon shafts 24 journalled inbearing brackets se-v cured to and' extending up'fro'm otherffstaf tionary'franie members126b. iThescreen 2l; 'i Y h as bearingl shoes; 23@ secured to thel lowcr sides of.l the le'ngthwise-*Jextending Lscreen frame members 2T, against. which shoesthe cams strikeand throw the screen upwardly each time ythe working faces ofthe cams engage the` bearing shoes. Balance wheels 24a may be mounted-on the shafts 24.3 f. The-shafts 24n1ay` befdrivenfrom-any suitable source ofpower,` and,A ais-showinl they are connected byi-a sprocketchain 15,r

train'edfaround sprocket whee-lsw 22, on 'the shafts.:` A driving sprocket chain j2M() trained around a sprocket wheel on'one of the 'shafts may be employed for rotating the' cam shafts.y lSaid' cams .strike the shoesv and throw the screen upward andthe cushions;

ing deviceis provided to receive the iinpact from the screen, when it ldrops s after beingstruck upward by the cams. lnfsome' instances the cams arev provided only atA .the

' lower end of thescrleen and invsuch casewtheI cushioningl devices are" provided; only at they Vlower end. The cushioning means employedwill now bedescribed. f

lnthe,transverse.- frame-beams .--26nare i formed a lplurality .of sockets or. recesses 32 (see Eig. 4l) which extend5down from the upper face of said vbeams `and inf-each. v

of; said sockets is placed a short tube or', pipe 33` which forms-a liningfor' facingffor. the. wall ofthe socket. Below' thetube-.or pipe 33, al block` or plate. 34: is' letginto tlieebeam,v which, block q (Jr-plate Iis 4:v provided 'withA athreaded aperture iin `'which f is j i threadedly;

mounted@manv adjusting screw A35. a.Resting upon the upper end of each screw is 'a'disc 36, and resting on said disc 1s a coiled com- Springis a second disc 38 upon which pression springk 37. 'Supportedbyifxsaid rests a block 39 formed ofru-bberor other resilient material. Said rubber block protrudes from the tube or pipe 32 and receives the impact from the screen, each time it falls after being struck up by the cams. The several cushioning members are spaced along the beam 26a and as many may be employed as is found necessary for properlyy cushioning the load.

The screen frame with its screen is held against lengthwise movement by links 40, which may be in the form of bars or cables attached to the stationary frame members- 261 and the screen frame by brackets 4l, 42 or other suitable fastening devices. Fon convenience, I have shown rods 44, 43, for` connecting the links to the brackets 4l, 42. This link connection between the stationary frame and inclined screen frame permits of the up and down vibratory movements imparted to it by the cams, but hold-s it against lengthwise movement, preventing it from sliding down on the cams. Said links eX- tend in lines approximately` parallel with the screen, whereby the movement of the latter may be substantially in line with the cushioning devices, thereby minimizing the wear on the cushioning blocks. WVi-th this arrangement, the screen frame strikes them squarely on their ends and does not causeany rubbing action thereon.

F or preventing any side play of the screen I provide lguide members at the corners CII thereof, said guide members comprising angle iron pieces 45 mounted on blocks 46 carried by the frame members 26h. Said angle iron pieces extend up along' the outer sides of the screen frame and prevent any side play thereof;

It will be observed that the cushioning members receive theshock and impact whenv the screen falls after being struck upward by the cams, and that by adjusting the position of the cushioning blocks 39 more or less fall may be given tothe screen, which enables the screen to act more orless violently upon the material, depending upon the character of the material which is being screened.

I have found that screens equipped with these cushioning members out-last others considerably; they are less noisy and are not subject to the usual shocks and jars to which they heretofore were.

AMore or less-variation of the exact details of construction ispossible without departing from the spirit ofl this invention; I desire, therefore, notte limit myself to the exact formv of construction shown and described,

but inten-d, inthefollowing claims, to pointout all l0f the. invention disclosed. here-in.

I claim as new and desire to secure by Letters Patent:

1. In a screening apparatus, the combination of a stationary frame having a horizontal frame member, an inclined screen frame and a` screen carried thereby, a cam shaft mounted on said stationary frame, screen agitaing'l cams mounted on said sha-ft, and a plura. ity of resilient cushioning members spaced along and mounted in and proj ectingupward and out from said horizontal frame member under one end of said screen frame, and adaptedto receive impact from the screen.

2. In a screening apparatus, the combination of a stationary frame having a horizontal frame member, an inclined screen frame and a. screen carried thereby, a cam shaft mounted on said stationary frame, screen agitating cams mounted on said shaft, a plurality rof' separately adjustable adjusting' screws mounted in said horizontal frame member under saidscreen frame, discs on said screws, coiled compression springs, con-4 fined in recesses and resting on said discs, other discs resting on said springs, and blocks of resilient material resting on said last mentioned discs and projecting upward and out from said frame member, said springs and blocksacting to receive impact from said screen.

3. In a screening apparatus, the combination of a stationaryframe having a wooden horizontal frame member, an inclined screen frame and a screen carried thereby, a cam shaft mounted on said stationary frame, screen agitating cams mounted on said shaft, said horizontal frame member being formed with recesses under said end of said screen frame, tubes in said! recesses, screw carrying blocks secured in said horizontal frame memberl below said recesses, adjusting screws threaded in said blocks, coiled compression springs in said tubes and supportedby said screws, and blocks of resilient material sup ported by said springs and protruding from said tubes and adaptedv to receive impact fromrsaid screen.

` 4. In a screening apparatus, the combination of a stationary frame, an inclined screen frame and a screen carried thereby,

cam shafts mounted on said stationary frame adjacent each end of' said screen and screen agitatingcams mounted on said' shafts, and'j link connections between said station` ary frame. and screen frameA secured tothe screen frame intermediate the upper and lower cams, for-holding said screenA frame.

against end'wi'se movement.

raun- @wenn 

